Vigabatrin, a GABA aminotransferase (GABA-AT) inactivator, is used to treat infantile spasms and refractory complex partial seizures, and is in clinical trials by Catalyst to treat cocaine addiction. In the trial, cocaine addicts were randomized to receive either vigabatrin 1.5g/bid, cumulative dose 218g (n=92), or placebo (n=94) for 12 weeks. Subjects underwent examination of visual acuity (ETDRS) and peripheral visual field (PVF) by Humphrey Field Analyzer (HFA 60-4 program) before and after treatment. Main outcome measures included visual acuity decrease by 15 letters and/or significant PVF alteration, defined as five or more visual field location points having greater than or equal to 15dB reduction or decline (≥33% loss) in post-treatment PVF for one or more rings, both of which constitute the minimum change needed to be considered clinically significant as defined by the
American Medical Association.

Results

Visual acuity decrease was detected in one eye of a subject receiving placebo and in none receiving vigabatrin. Post-treatment reduction of more than 15dB in five or more adjacent visual field location points combined with reduction of greater than 33% in one or more of the rings was detected in 2 of 54 subjects (3.7%) from the vigabatrin group versus 1 of 49 subjects (2%) from the placebo group (P=.9, NS). None of the PVF changes were bilateral or concentric, a hallmark of the changes previously reported to result from the long-term, chronic use of vigabatrin.

Conclusion

Short-term use of vigabatrin did not cause a decrease in visual acuity or significant peripheral visual field changes in cocaine abusers. These results confirm and expand upon previously published ocular safety results obtained in a study conducted by Dr. Fechtner and colleagues (Fechtner et al., Arch Ophthalmol 2006; 124:1257-62).

About the American Journal of Ophthalmology

The American Journal of Ophthalmology is a peer-reviewed, scientific publication that welcomes the submission of original, previously unpublished manuscripts directed to ophthalmologists and visual science specialists describing clinical investigations, clinical observations and clinically relevant laboratory investigations. Published monthly since 1884, the full text of the American Journal of Ophthalmology and supplementary material are also presented on the Internet at www.AJO.com.

About Catalyst Pharmaceutical Partners

Catalyst Pharmaceutical Partners, Inc. is a development-stage specialty pharmaceutical company focused on the development and commercialization of prescription drugs targeting diseases and disorders of the central nervous system, including addiction and epilepsy. Catalyst has two products in development, and is currently evaluating its lead product and first-in-class GABA aminotransferase inhibitor candidate, CPP-109 (vigabatrin), for the treatment of cocaine addiction. CPP-109 has been granted "Fast Track" status by the U.S. Food & Drug Administration (FDA) for the treatment of cocaine dependency. Catalyst also expects to evaluate CPP-109 for the treatment of other addictions. Catalyst is also developing CPP-115, a next-generation GABA aminotransferase inhibitor, which is more
potent than vigabatrin and has reduced side effects from those associated with vigabatrin. Catalyst is planning to develop CPP-115 for several indications, including addiction, epilepsy and other CNS indications. CPP-115 has been designated as a "Fast Track" development program for the treatment of cocaine addiction and has been granted orphan drug designation for the treatment of infantile spasms, both by the FDA. CPP-115 has also been granted orphan medicinal product designation by the European Commission for the treatment of West Syndrome. For more information about Catalyst, go to www.catalystpharma.com.

Forward-Looking Statements

This press release contains forward-looking statements. Forward-looking statements involve known and unknown risks and uncertainties, which may cause the Company's actual results in future periods to differ materially from forecasted results. A number of factors, including whether CPP-109 or CPP-115 will ever be approved for commercialization, and those described in the Company's filings with the U.S. Securities and Exchange Commission ("SEC"), could adversely affect the Company. Copies of the Company's filings with the SEC are available from the SEC, may be found on the Company's website or may be obtained upon request from the Company. The Company does not undertake any obligation to update the information contained herein, which speaks only as of this date.